Heretofore, yarn brakes of this type have been proposed, as for example in German Patent Specifications OS No. 2 309 578, AS Nos. 25 43 018 and 1 510 807, which utilize a brake housing defining a yarn passageway therethrough and having a braking body movably positioned within the passageway for contact with upper and lower braking rings surrounding the passageway to apply tension to a yarn moving through the brake mechanism. One of the braking rings may be axially movable in this type of brake mechanism under the influence of a mechanical or pneumatic force or other mechanisms may be provided for separation of the braking body from the braking rings to open the passageway through the brake mechanism for manual or pneumatic threading of the yarn through the brake mechanism.
All of the yarn brakes of the above-discussed general type known to applicant, and including the yarn brakes of the aforementioned German Patent Specifications, are susceptible to problems with respect to re-establishing good or proper braking engagement between the braking body and the braking rings. In all of these types of yarn brakes, the braking body is laterally moved to some extent out of alignment with the braking surfaces of the braking rings during the threading operation of the yarn brake and may become tilted or inclined during return of the braking body into its axially-aligned position with the braking surfaces of the braking rings. This is particularly acute in the case of the use of a magnetic means for holding the braking body out of braking position with the braking rings during threading up of the yarn brake, such as is disclosed in German Patent Specification OS No. 2 309 578, due to the possibility of the braking body being unevenly detatched from the magnetic means retaining it when it is desired to return the braking body to an axially-aligned position in braking engagement with the braking rings. Additionally, the provision of such a magnetic means involves additional constructional expenses.